Hearing-impaired individuals may benefit from communication systems and devices configured to provide assistance in order to communicate with other individuals over a communication network. For example, captioning communication services have been established to provide assistive services (e.g., text captions) to the hearing-impaired user communicating with a communication device (e.g., caption phone, caption enabled device, etc.) that is specifically configured to communicate with the captioning communication service.
In particular, a captioning communication service may be a telecommunication assistive service, which is intended to permit a hearing-impaired person to utilize a communication network and assist their understanding of a conversation by providing text captions to supplement the voice conversation. The captioning communication service may include an operator, referred to as a “call assistant,” who serves as a human intermediary between the hearing-impaired user and a far-end user. During a captioning communication session, the call assistant may listen to the audio signal of a far-end user and “revoice” the words of the far-end user to a speech recognition computer program tuned to the voice of the call assistant. Text captions (also referred to as “captions”) may be generated by the speech recognition computer as a transcription of the audio signal of the far-end user, and then transmitted to the communication device being used by the hearing-impaired user. The communication device may then display the text captions while the hearing-impaired user carries on a normal conversation with the far-end user. The text captions may allow the hearing-impaired user to supplement the voice received from the far-end and confirm his or her understanding of the words spoken by the far-end user.
During a communication session, the communication device may experience echo (e.g., hybrid echo, acoustic echo, etc.). The term “hybrid echo” (also referred to as “electric echo”) describes a phenomenon in which a fraction of the signal leaving the phone is reflected by a hybrid circuit and returns into the near-end communication device. This is particularly prevalent in voice-band communication circuits where there are impedance imbalances in local two-wire to four-wire hybrid circuits are used. The effect of hybrid echo is that the near-end user hears their own utterances repeated back to them. Echo cancellation systems are conventionally employed within communication devices to cancel hybrid echo and/or acoustic echo.